Method of tubulating



Feb. 10, 1942.

L. L. STAGER METHOD OF TABULATING Filed Sept. 15, 1958 INVENTOR 2. L. sTAaE/e ATTORNEY Patented Feb. 10, 1942 UNITED STATES PATENT oFFicE Application September 15, 1938, Serial No. 230,044

3 Claims.

This invention relates to a method of tubulating, and more particularly to a method of tubulating glass bulbs.

An object of the invention is to provide a simple, eflicient and practical method of tubulating. With this and other objects in view, the method comprises applying heat within a glass bulb to soften an area thereofagainst the outer Y surface of which a glass tube is pressed until it moves a predetermined distance, at which time air is forced into the tube to puncture the softened glass over the inner end thereof, the continued application of heat causing the softened material to fiare outwardly and form a fused connection between the tube and the bulb.

Other objects and advantages will be apparent from the following detailed description taken in conjunction with the accompanying drawing, wherein Figs. 1 to 5 inclusive illustrate the results of various steps of the method.

Referring now to the drawing, particularly Fig. l, a bulb It, to which a tube II is to be connected, is disposed over a burner It, the latter being any suitable heat supplying means such as the conventional type of gas burner employed in the art of lamp making.

The tube ll is removably disposed in a socket l3, where it is rigidly held against relative movement until the completion of the method. The socket l3, through its connection with an arm 14 and a sleeve I5, is movable relative to a rod IS, the sleeve l5 being slidably disposed upon the rod and normally urged toward a stop I], fixed to the rod, by means of a compression spring I8, the latter being disposed concentric with the rod between the sleeve [5 and a fixed shoulder- 20. An arm 2| upon which the rod I6 is rigidly mounted is positioned to be moved by any suitable means (not shown), a predetermined distance, after tube H is disposed in the socket l3 to bring the lower 'end of the tube into engagement with the bulb at a predetermined time and to compress the spring l8 to apply a desired pressure of the tube on the bulb and to position the stop I! to limit movement of the sleeve l5 as well as the tube for a purpose hereinafter described.

When the tube- H is in the position shown in 1 heat is applied within the bulb sothat that portion of the bulb adjacent the lower end of the tube becomes softened. The pressure of the spring will then cause movement of the tube downwardly, as illustrated in Fig. 2, until the sleeve comes to-fest, upon the stop I1, thus locating the tube relative to the-bulb for fusing.

The heat is continuously applied and at the next step of the method, as illustrated in Fig. 3, air under pressure is directed through the tube to cause the softened glass of the bulb to expand in the form of a bubble to the point 'of breaking, as illustrated in Fig. 4. The air under pressure may be supplied through the aid of any suitable supply means, such as that indicated at 25.

The softened material surrounding the aperture, resulting from the application of air under pressure through the tube, is flared outwardly, as illustrated in Fig. 4, and through-the continuous application of the heat this material is fused into the top of the bulb, forming a perfect seal between the tube and the bulb. After the final step of the method, illustrated in Fig. 5, the tube holding means may be moved vertically to remove the tubulated bulb from the burner.

In reviewing the steps of the method, the bulb I 2 is placed over the burner and the tube in its holding means is moved into engagement with a desired portion of the bulb to which it is to be secured. As the steps of the method continue, the pressure of the spring causes the tube to move inwardly a definite limited distance as soon as the glass at the heated portion is softened sufficiently, at which time air under pressure is directed through the tube, causing the softened material of the bulb to expand until it breaks, forming an outwardly flared portion around the lower'portion of the tube which at this stage has been fused to the bulb, yet the continued application of heat causes the outwardly flared material shown in Fig. 4 to melt overand become fused, as illustrated in Fig. 5.

In tubulating the bulb according to, this method the heat is applied to the inner surface of the bulb in direct alignment with the tube. Furthermore, without moving the heating means 40 during movement of the tube the central or hot-.

test portion of the flame is applied, throughout the method, at the point adjacent the tube and heat is applied only to that portion of the bulb and tube necessary to be softened. The embodiment of the invention herein disclosed is illustrative only and may be widely modified and departed from in many ways without departing from the spirit and scope of the invention as pointed out in and limited only by the appended claims.

What is claimed is: 1. A method of tubulating bulbs comprising placing a tube with one end in engagement with the outer surface of a portion of a bulb, applying a forced fiame to the inner surface of the the outer surface of a portion of a bulb, applying a forced flame to the inner surface of the said portion in alignment with the tube to uniformly soften the portion at the tube and the end of the tube engaging the portion, forcing the tube longitudinally toward the flame in a direction-opposite the direction of force of the flame, limiting the movement ofthe tube, applying air under pressure through the tube to .break the softened portion against the flame to maintain a uniform opening through the tube, and fusing the tube to the bulb.

3. A method of tubulating bulbs comprising placing a tube with one end engagins the outer surface of a portion of a bulb under pressure, applying a forced flame to the inner surface of the said portion in alignment with the tube to uniformly soften the portion at the tube and the end of the tube engaging the portion, forcing the tube toward the flame, limiting the movement of the tube, applying air under pressure through the tube to breakthe softened portion against the flame to maintain a uniform opening through the tube, and fusing the tube to the bulb.

LUKE L. STAGER. 

